Graphite Negative Plate for High-Density Battery Wettability
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Solution Overview
Problem
Current battery technologies face a trade-off between high compacted density for improved energy density and low-temperature wettability, where increasing compacted density often decreases low-temperature liquid absorption capacity and cycle life.
Innovation Solution
A negative plate design with a specific particle size distribution, crystal size, and compacted density, optimized through relationships involving full width at half maximum, particle diameter, and ion transport impedance, ensures high compacted density while maintaining good low-temperature wettability and electrolyte absorption capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the compacted density of the plates is increased to improve energy density, then the energy density of the battery is improved, but the low-temperature liquid absorption capacity (wettability) of the plates decreases
Solution Approach 1:
The patent applies parameter changes by precisely controlling the particle size distribution parameters (DFW and DV50) of the anode active material and the crystal size parameter (La) to optimize the compacted density while maintaining low-temperature wettability. By adjusting these parameters within specific ranges, the invention achieves high energy density without sacrificing low-temperature liquid absorption capacity.
Solution Approach 2:
The patent uses composite materials by combining anode active material particles with specific size distributions and crystal structures with a current collector to form a composite electrode structure. This composite approach allows the system to achieve both high compacted density for improved energy density and maintained wettability through the synergistic effects of the material composition.
2Quantity of substance
If the compacted density of the plates is increased to improve energy density, then the energy density of the battery is improved, but the cycle life of the battery decreases
Solution Approach 1:
The patent applies parameter changes by optimizing the particle size distribution (DFW, DV50) and crystal size (La) parameters to achieve a balanced compacted density that improves energy density while preserving cycle life. The specific parameter ranges ensure that the electrode structure remains stable over multiple charge-discharge cycles.
Solution Approach 2:
The patent employs composite materials with specific structural characteristics - anode active material with controlled particle size distribution and crystal structure combined with current collector - to create an electrode that simultaneously achieves high energy density and extended cycle life through the synergistic properties of the composite structure.
3Reliability
If the particle size of the anode active material is reduced to improve wettability, then the low-temperature liquid absorption capacity is improved, but the compacted density of the plate decreases
Solution Approach 1:
The patent applies parameter changes by controlling the particle size distribution parameters (DFW and DV50) within specific ranges to achieve an optimal balance between low-temperature wettability and compacted density. Rather than simply reducing particle size, the invention optimizes the distribution of particle sizes to maintain both wettability and density.
Solution Approach 2:
The patent applies local quality by creating different particle size distributions in different regions of the anode active material layer. The particle size distribution is optimized locally to ensure good wettability at the surface while maintaining high compacted density in the bulk structure.
4Reliability
If the crystal size in the a-axis direction is reduced to improve ion transport, then the ion transport impedance is reduced, but the manufacturing precision requirements increase
Solution Approach 1:
The patent applies parameter changes by controlling the crystal size parameter (La) within a specific range to optimize ion transport impedance while maintaining feasible manufacturing precision requirements. The selected range balances the need for low ion transport impedance with the practical constraints of manufacturing control.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The optimized negative plate achieves a balance between high energy density and extended cycle life, with improved lithium ion intercalation and deintercalation efficiency and enhanced wetting performance at low temperatures.
Implementation Method 1
the negative plate has a higher compacted density, maintains a good low-temperature wettability, and has a good liquid absorption capacity for an electrolyte solution at a low temperature
Implementation Method 2
improved lithium ion intercalation and deintercalation efficiency
Data Source
AI summary
A negative plate, a secondary battery and an electrical device, which fall within the technical field of batteries, wherein the negative plate includes a negative current collector and an anode active material layer provided on a surface of the negative current collector, the anode active material layer includes an anode active material, the anode active material includes graphite, and the negative plate satisfies the following relationship: a=ln(DFW)+10×ln(DV50)+⅓(La)+26.5, b=PD, a/45−b≥0.05. By reasonably controlling a particle diameter distribution of the anode active material in the negative plate, as well as a crystal size and a compacted density of the negative plate, the negative plate of the present disclosure maintains good wettability at a higher compacted density and has good liquid absorption capacity for an electrolyte solution, and a battery containing the negative plate has excellent cycle life.